I'm truly confused, any input would help

The first day of my last period was 8/28 ending on 9/1....Took ovulating test and showed positive on 9/5 (just ⁴days after my period) I still have not got AF but BFN on my HCG test, but keep testing positive on LH test could I barley get pregnant now on just conceive in October? The doctor thinks I miscalculated AF and wants to wait two more weeks before blood test. Any input would be greatly appreciate basically should we BD as normally trying when positive opk??????? THANKS ladies